This invention relates to a multiple valve engine and more particularly to an improved induction system for an internal combustion engine having multiple intake valves.
It is well known that the specific output of an internal combustion engine can be increased by using two or more intake valves for each combustion engine rather than the more conventional single intake valve. The use of multiple intake valves provides a greater valve opening area than with a single valve and also permits higher running speed due to the lower inertia of the multiple, but smaller valves. Thus, it is common practice to employ two or sometimes even three intake valves per chamber for high performance engines.
The advantages of multiple intake valves can also be enjoyed with more conventional power plants such as those utilized to propel normal automobiles or motorcyles of other than the high performance type. However, the use of multiple intake valves of the type previously proposed tends to provide extremely poor running under slow speed conditions. The reason for this is that the gas velocity through the induction tract is very slow at low engine speeds and fuel has a tendency to condense on the induction passages and within the combustion chamber. In addition, the flow of the intake charge into the combustion chamber is very sluggish and this results in very slow flame travel and incomplete combustion.
It is, therefore, a principal object of this invention to provide an improved induction system for an internal combustion engine that will improve its performance throughout the entire engine load and speed ranges.
It is another object of this invention to provide an induction system for a multiple intake valve engine that provides good running characteristics at low speeds.